Is the machine level? It has two probes for water level Any time the high probe does not touch the water in the first 6 minuets of freeze the machine will add.water to the probe.

Are the probes correctly mounted? And clean. The machine should be clean of any minerals. Check around the thickness sensor. The Probe bracket has slots for adjustment.

Are the probes plugged into the control board?

Is the solenoid leaking water in the off position? Does the machine gain water when off.

Is the machine drain line clear? Overflow will not go into the bin if the drain is clear and the machine is level.. It will go down the overflow line. The only other way water will get into the bin is if the spray bars are wrong or the cover is open.